Coupling between Geomagnetic Field and Earth’s Climate System

Abstract

The idea about synchronized variations of geomagnetic field and climate appears in the middle of the twentieth century. Among others, one of the main reasons for its unpopularity is the missing mechanism of coupling between magnetic and non-magnetic media. This chapter offers such a mechanism, consisting of a chain of relations transmitting the geomagnetic spatial-temporal variations down to the planetary surface. The first element of this chain is energetic particles propagating in Earth’s atmosphere, whose density and depth of penetration are modulated by geomagnetic field. Thus, the non-dipolar geomagnetic irregularities are projected on the ionization layer in the lower atmosphere (known as Regener-Pfotzer maximum). This unevenly distributed ionization, in certain conditions (i.e. dry atmosphere), acts as a secondary source of ozone near the tropopause. Ozone at this level is of special importance due to its influence on the tropopause temperature and humidity, and consequently on the planetary radiation balance. Hence, the geomagnetic spatial and temporal variations are imprinted down to the surface, impacting the climate system and its regional structures. The chapter provides synthesized information about geomagnetic field variability, particles’ propagation in Earth’s atmosphere, ion-molecular reactions initiating ozone formation in the lower stratosphere, as well as evidence for its covariance with some atmospheric variables.

Impact of Forbush Decreases and Geomagnetic Storms on the Atmospheric Ozone Profiles

“…Analysis of Figures 8 and 9 shows that the greatest ozone and pressure anomalies related to the FDs are visible in the latitudinal band 50°–70°N. Our previous analyses (Kilifarska, Bakhmutov, & Melnyk, 2022) reveal that at these latitudes is detected a centennial enhancement of ozone at 70 hPa between the first decades of 20 and 21st centuries. The strongest ozone impact on the sea level pressure, within the period 1900–2019, is found exactly in the same region (Kilifarska, Velichkova, & Mokreva, 2022).…”

“…The spatial heterogeneity of geomagnetic field suggests that energetic particles reaching the lower atmosphere are also unevenly distributed over the globe (Kilifarska, Bakhmutov, & Melnyk, 2022). To reveal any differences in ozone response to depleted particles' flux during geomagnetic storms and/or FDs, we have to compare regions with different particles' intensity.…”

The Simultaneous Influence of the Solar Wind and Earth’s Magnetic Field on the Weather

“…The authors of [22] explain that the non-dipolar geomagnetic irregularities are the reason for the projection of ionizing particles into the lower ozone layer (near the troposphere). This results in a direct effect on the tropopause temperature and humidity.…”